A. Field of Invention
The present invention is directed to a toe shoe, and more specifically, to a toe shoe capable of providing support to a ballet dancer's foot, toes, and ankle during en pointe dancing.
B. Description of the Related Art
The design and materials of the traditional toe shoe, also known as a “pointe shoe,” have remained virtually unchanged for centuries. Generally made by hand, the traditional toe shoe utilizes layers of fabric, burlap, cardboard, paper, plastic, leather, or any combination thereof. The layers of material may be saturated with glue to form a reinforced toe box. A hard insole, called a “shank,” and an outer sole are attached to the toe box. Glue, stitching, small nails, or any combinations thereof, hold the toe shoe together. A fabric upper, usually a pink satin material, covers the toe shoe. Satin ribbons or elastic straps are often sewn to the sides of the toe shoe and tied or secured around the ballet dancer's ankle to ensure that the toe shoe remains on the dancer's foot.
Although the traditional toe shoe has been used by many generations of ballet dancers, the traditional toe shoe is known in the art to be uncomfortable, even painful. The toe box compresses the sides of the foot, often exacerbating problems that are associated with the hopping and leaping en pointe required by ballet choreography. Further, traditional toe shoes lack shock absorption, offering no protection to the ballet dancer who must repeatedly jump during the course of a performance or practice.
General principles of physics illustrate how dancing en pointe, when performed in traditional toe shoes, creates forces that act on the body of the ballet dancer. It is believed that these forces contribute to the daily wear and tear on a dancer's body, and specifically, to the dancer's toes, feet, and ankles.
For example, ballet dancing involves movements of the dancer's body interspersed with motionless poses. When a ballet dancer dancing en pointe is positioned in a motionless pose, the sum of all forces and torques acting on the dancer's body is approximately zero. This means that the dancer's center of gravity lies on a vertical line that passes from the dancer's body down to the area of support, which is the dancer's foot, toes, and ankle. This downwardly directed force of gravity is balanced by a force rising upward from the floor on that same vertical line. Therefore, the dancer's foot, toes, and ankle are subject to a force that is at least equal to the dancer's weight. This force may increase as the dancer accelerates from a flat-footed position to an en pointe position while practicing or performing.
Ballet dancing also involves turns en pointe, which are commonly known in the art as pirouettes on the point of a ballet dancer's toe shoes. Pirouettes specifically require turns on the front end of the toe box of the toe shoe. The pirouette begins with a preparatory position. The dancer then rotates her arms, torso, and legs with respect to the floor. The twisting force or torque of the dancer's body is carried into the floor by her foot, which allows her to produce the turning motion of the pirouette as she goes from the sole of her foot to en pointe. The upward torque from the floor against the dancer causes an angular acceleration that produces the turning motion. The dancer's toes, feet, and ankles absorb the brunt of the floor's torque.
In addition to forces acting on the ballet dancer's toes, foot, and ankle, there is upward tension in a dancer's achilles tendon because the dancer must push her toes down into the floor in order to remain en pointe while dancing. This tension in the achilles tendon increases as a dancer accelerates from a flat-footed position to an en pointe position, which requires the dancer to push her toes down and lift her heel up. As a result, the achilles tendon must withstand a tension force two to three times the dancer's body weight. With a traditional toe shoe, this tension force is carried longitudinally through the dancer's arched foot to her ankle and leg.
The forces acting on ballet dancers' toes, feet, and ankles, along with the construction of traditional toe shoes, contribute to a number of dancing-related injuries. These injuries include, but are not limited to bunions, blisters, corns, crooked toes, potential or actual stress fractures, tendinitis, sprains, metatarsal bruises, bruises, toe dislocations, and early onset of arthritis. While some of these injuries are relatively minor and heal quickly, other injuries can end a ballet dancer's career.
There have been many attempts to improve upon the traditional toe shoe. U.S. Pat. No. 5,191,726 to Vallee (the “Vallee reference”); U.S. Pat. No. 5,740,618 to Minden (the “Minden '618 reference”); U.S. Pat. No. 5,035,069 to Minden (the “Minden '069 reference”); and U.S. Pat. No. 4,901,453 to Gaynor (the “Gaynor reference”) are exemplary of these attempts and are described to show the current state of the art.
The Vallee reference sets forth a ballet shoe designed specifically for either the left or right foot. The shoe is composed of a sole, a flexible upper that is fixed to the sole, and a vamp that is adapted to surround the front part of the foot. The upper is designed so that points of maximum height of the shoe are located to one side of a longitudinal plane of the shoe, while a flat widening of the shoe occurs on the other side of the longitudinal plane, thereby creating a shoe that is specifically intended for either the left or right foot of a dancer.
The Minden '618 reference sets forth a dance shoe having a toe box that is integrally formed with a shank. Within the toe box are removable foam pads that may be located in at least one of the left and right side surfaces of the toe box, against both the left and right side surfaces of the toe box, or covering the top surface and the left and right side surfaces of the toe box. The foam pads are composed of a dynamic foam pad with a low-compression set, such that the foam pad is compressed by a dancer's foot when the foot is in the flat standing position and expands when the dancer is standing en pointe.
The Minden '069 reference sets forth a ballet slipper having a shank and toe box molded from a thermoplastic polymeric material. The toe box is composed of a platform exterior surface at the forward end of the toe box, a curved radius exterior surface joining the platform, and the lower surface of the shank. The shoe further discloses a layer of resilient, shock-absorbing polymeric material that covers at least a portion of at least one of the lower surfaces of the shank, the exterior surface of the platform, and the exterior surface of the radius of the toe box.
The Gaynor reference sets forth a ballet slipper having a shank and toe box molded from a thermoplastic polymeric material. When the thermoplastic polymeric material is heated, the material softens, thereby allowing the dancer to adjust the shank and toe box to his or her foot. The toe box includes a platform at its forward end and a curved radius joining the platform and the toe box. The ballet slipper has a polymeric material that lines the interior portion of the toe box and extends backwards from the edges of the toe box. A shock-absorbing polymeric material covers the exterior surface of the curved radius and the platform.
Additionally, there have been several general-footwear companies that have focused on caring for feet by providing footwear and foot bed inserts that conform to the shape of the wearer's foot for the purposes of walking or running. Such general footwear, which include sandals, clogs, ski boots, skates, and shoes, is constructed to match the shape of the wearer's foot. The general footwear and foot bed inserts are designed so that when the wearer is walking upright, the wearer's foot is in as natural a position as it would be if the wearer were walking barefoot.
One example of this type of general footwear is the BIRKENSTOCK® sandal, manufactured by Birkenstock Orthopadie of Germany. In addition to being in the shape of a regular foot, the BIRKENSTOCK® sandal has a natural-shaped footbed that allows room for the foot to maintain a normal position while walking. Additionally, a BIRKENSTOCK® sandal usually implements a raised toe bar. The toe bar encourages the natural gripping motion of the wearer's foot, exercises the legs, and improves circulation while the wearer is walking. The BIRKENSTOCK® sandal further contains an arch support that ensures even weight distribution and proper support of the wearer's foot. Finally, the BIRKENSTOCK® sandal contains a deep heelcup, which keeps the foot's natural padding directly under the heelbone. The toe bar, arch support, and deep heelcup are all provided in order to match the shape of the sandal with the shape of the wearer's foot.
The DR. SCHOLL'S® exercise sandal, manufactured by Scholl, Inc., a Delaware corporation, implements a contoured heel and toe grip. The heel and toe grip are provided to strengthen wearers' legs, feet, and ankles as they walk. The bottom half of the sandal is usually made of wood, and the sandal is manufactured such that wearers must grip the sandals with their toes when walking to ensure that the sandals do not slip off easily.
As a whole, the above-mentioned prior art is incapable of and improper for use in a ballet dance setting; it fails to provide the proper support to ballet dancers' feet, toes, and ankles during en pointe dancing; and it does not retain the aesthetic appearance of a traditional toe shoe.